GaAs Solar Cells with Conversion Efficiency of 24.7%

Posted by Ken Cheung in Research on Tuesday, April 15, 2008

IMEC recently announced a single-junction GaAs solar cell on a Ge substrate with a record conversion efficiency of 24.7%. The efficiency was measured and confirmed by the National Renewable Energy Laboratory, USA (NREL). GaAs solar cells are used in satellite solar panels and earth-based solar concentrators.

IMEC realized this record on a single-junction GaAs cell, grown epitaxially on a Ge substrate with an improved micro-defect distribution. The record cell measures 0.25cm², and shows an efficiency of 24.7%, with an open-circuit voltage of 999mV, a short-circuit current of 29.7 mA/cm (squared), and a fill factor of 83.2%. The cell was made under the ESA-IMAGER project. Umicore, a leading materials technology group, produced the Ge substrate through an optimized manufacturing technology, aimed at improving the intrinsic germanium crystal quality.

Improving the efficiency of this single-junction GaAs cell is a further step in the development of a hybrid monolithic/mechanically stacked triple-junction solar cell. This type of solar cells consists of stacks of solar cells made of different semiconductors, carefully chosen to absorb the solar spectrum as efficiently as possible. Among the many possible combinations, IMEC focuses on stacked cells consisting of top cells with III-V materials and bottom cells made from Ge.

With this combination, IMEC is targeting a conversion efficiency of 35% and more. The resulting stacks can be used in satellites and earth-based concentrators, where high-efficiency energy conversion is paramount.

More info: IMEC

If you found this page useful, bookmark and share it on:

Possibly of Interest

 
EDA Blog Newsletter
Don't have time to visit EDA Blog everyday? Then sign up for our free newsletter. We'll send you an email when we have something to share with you. Your email address will be kept confidential and we will not share, sell, or rent it to anyone. You can unsubscribe at any time by clicking a link in the email.

Enter your email address to sign up for our free newsletter:   

If you are familiar with RSS feeds, you can also sign up for our free blog feed. Our RSS feed is updated in real-time while our newsletter is updated daily.